That Facebook Pride filter was built by 2 interns in 72 hours

Last Friday, after the Supreme Court legalized gay marriage nationwide, many showed their supported for the decision on Facebook by adding a Rainbow Pride flag filter to their profile picture.

Over the weekend, more than 26 million people used the filter, Facebook said in a post about the project.

It was a proud moment for the two interns who built the tool during a recent Facebook hackathon, inspired by a flag that was waving on Facebook's Menlo Park campus during June's Gay Pride month.

They had released the tool internally for Facebook employees and it was so popular, they wanted to make it available to everybody, getting it ready for the Gay Pride celebration scheduled for San Francisco on June 27-28.

When SCOTUS announced the decision Friday morning, they hustled to push the tool out to everyone.

And it promptly broke. A lot of people couldn't get it to work, Facebook admitted in a post about the tech used to build the tool.

While they did a good job planning for the tool to be used more on mobile devices than the web (which it was), they hadn't planned on people using it for some of the really big pictures they posted to Facebook.

Once they figured out the problem, boom! Gay pride filters popped up all over Facebook. From start to finish, creating the tool and pushing it out globally took 72 hours, Facebook says.

As we previously reported, Facebook also painted its famous headquarters sign in Menlo Park, California into a rainbow in honor of Pride, too. Here's a photo of that sign from last weekend: